Sympathetic nerves are located on the front and side of the spinal column. Part of the autonomic nervous system, these nerves are responsible for controlling many important functions such as heart rate, movement, and sweating. When it comes to spine pain, some patients report continued discomfort even when the initial source of the pain has healed. This happens when the sympathetic nerves send pain information back to the spine via peripheral tissues. The purpose of a lumbar sympathetic block is either to confirm a suspected source of nerve-related pain or to manage it.
Why Lumbar Sympathetic Blocks Are Done
A nerve block is often recommended for patients with peripheral vascular disease or neuropathy (radiating nerve pain) felt in the legs. Since leg pain may also be due to sciatica (pressure on the sciatic nerve), the block may be diagnostic in nature to confirm or rule out the sympathetic nerves as a pain source.
How the Block Is Performed
Performed with local anesthesia, a lumbar sympathetic block may include steroid medication to extend the effects of the shot. If it’s being done for diagnostic purposes only, the injection may only have the anesthetic in it. A special live X-ray called is used to guide placement of the thin needle that’s inserted in the affected area. The actual procedure usually takes about 15-30 minutes to complete.
How Long Effects Last
It usually takes a few hours for the local anesthetic to wear off. If the procedure is being done for pain relief purposes, results will typically last longer if a steroid medication was also used.
Precautions to Consider and Results to Expect
Patients may be advised to stop talking certain medications prior to having a lumbar sympathetic block, especially blood thinners that may contribute to increased bleeding when the needle is inserted. If the right nerve is targeted, patients may report immediate relief while still under the effects of the local anesthesia. If this is the case, it can be assumed with some degree of certainty that it’s the sympathetic nerves causing the reported discomfort.
Recovery from a lumbar sympathetic block takes about an hour. During this time, patients are monitored. If the injection provides relief, additional treatments may be recommended. Some patients benefit from only a few treatments while others need multiple injections over a longer period of time. Risks are minimal. Some patients may experience slight discomfort at the injection site, but this is often temporary.